Folk physics is what everybody knows without taking any classes in physics.  It’s towels absorb water.  That if you throw a brick towards a plate of glass, it’s probably going to break the glass.  You can’t push a rope.  It’s what we learn about the everyday things in the world and how they react physically to things.  We don’t know it in terms of propositions, part of a theory.  We just have a lot of good expectations.  I know what’s gonna happen if you sit on a rotten tomato.  I know what’s gonna happen to that tomato.  That’s folk physics.

I know what’s going to happen if you try to pile up ten chairs high and then climb up to the top of it.  It won’t be stable.  That’s folk physics.  So what’s folk psychology?  It’s the same talent that we have for anticipating and understanding what we’re doing, what other people are doing when we see them.  

You go to a movie and you see two characters you’ve never seen before and usually if it’s a well-made movie, you’ve got a pretty good idea right off what they’re doing, who sees what, who knows what, what they’re trying to do.  It’s if somebody walks into a convenience store and takes out his wallet and points to something behind the counter, we know what this is – it’s a purchase.  And we don’t have to reason it out. We just see.  And so folk psychology is this almost instinctual talent we have for assessing out what somebody’s plans are, what their intentions are, what they know, what they want.

And mostly it’s obvious.  And even when it isn’t obvious we can usually frame it for ourselves as we need it.  And we use that to predict each other through the day.  It’s how we walk down the street without bumping into people.  It’s why we don’t hesitate to get in a car and go driving off on the highway at 60 miles an hour with cars coming towards us at 60 miles an hour in the opposite lane. We know they’re not gonna hit us.  How do we know that?  They could.  Physics says they could.  If you just use folk physics you’d be terrified.  But you know there’s people behind the wheel and you know that in general people want to stay alive and the best way to stay alive under these conditions is to stay on your own side of the road.  We make that prediction and it works flawlessly.

In Their Own Words is recorded in Big Think's studio.

Image courtesy of Shutterstock.